Incandescent-lamp socket



J. JJWOOD. INGANDESOENT LAMP SOCKET.

(No Model.)

No. 431,681. Patented July 8, 1890.

ATTORNEY R O T m V N I WITNESSES! Ya: mum Pwzu cm, mmmlmu, vushmavou, a. c.

UNITED STATES PATENT OFFICE.

JAMES J. WVOOD, OF BROOKLYN, NEW YORK.

lNCANDESCENT-LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 431,681, dated July 8, 1890.

Application filed Deccmber l4, 1887. Serial No. 257,868. (No model.)

To all whom it may concern:

Be it known that I, JAMES J. WOOD, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Electric-Lamp Holders, of which the following is a specification.

My invention relates more especially to holders for incandescent lamps used in series on constant-current or automaticallygov erned dynamos; and my improvements lie chiefly in safety devices to maintain the current to the other lamps in case of the breakage of any one lamp in the series, or. to insure the lighting of a second lamp in case its twin becomes broken.

My invention therefore consists, partly, in contact devices operated by the insertion of the lamp in the socket of the holder or by its removal therefrom and carrying a small disruptible cut-out device and in the special form of this cut-out device; also, in a small hand-switch to make a quick break between the terminals after the lamp is put in circuit to prevent arcing; also, in the combination of two lamps and a disrnptible cut-out between them, with paths between the cut-out and the two lamps so arranged that in case either lamp is broken the current is established to the other by disruption through the cut-out.

My invention therefore consists, mainly, in the features above outlined, as well as in the particular construction and combination of parts, as hereinafter fully set forth and claimed.

In the drawings annexed, Figure 1 is asectional elevation of my improved lamp-holder. Fig. 2 is a similar section,-but at right angles, or on line y y of Fig. 1. Fig. 3 is a cross-section or plan on line as of Figs. 1 and 2. Fig. 4 is a sectional detail of the cut-out, and Fig. 5 a detail of the hand-switch. Fig. 6 is a fragmentary external view of the holder. Fig. 7 is a diagram showing the cut-out applied to twin lamps, designed to maintain one in case the other breaks. Fig. 8 is a cross-section or plan of Figs. 1 and 2 below the line a; w, and Fig. 9 is an inverted plan on o 0.

Referring to the drawings, more especially Figs. 1, 2, and 6, it may be seen that in general external form and appearance the holder is similar to what is known as the Edison lamp-holder, and is formed with a screwsocket a to receive an Edison lamp.

b is the attaching base or head of the holder,

attached and which forms a fire-proof insulating-base'therefor. The slate disk e abuts on one side against two lugs or projections g 9, cast on and depending from the head I), (see Figs. 1 and 2,) and is secured to said lugs by the screws ff. (Seen in Figs. 3 and 9.) Now the screw-socketa at the mouth of the holder, which is, as usual, a short section of sheetmetal tube, in which a coarse round screwthread is spun,issecured metallically to a castmetal ring h, (seen best in Figs. 1, 2, and 9,) which ring has two prongs or legs k proj ecting therefrom, which are fastened by screws to the slate disk 0, as will be understood from Figs. 2, 3, 9, and 8. Now, at about right angles tothe legs k 70 of the ring h a small metallic bracket Z is fastened to the slate disk, which, curvin gdownwardly and inwardly, proj ects centrally between the legs 70 71; and terminates in a small vertical bearing Z, which is in line with the center of the slate disk 6 and the metal ring h, as fully shown in Figs. 1, 2, and 9. In this bearing Z is fitted a small vertical spindle m, the lower end of which terminates with a slotted head on, which projects down through the center of the ring h over the center of the screw-socket a, and 7 hence in the path of the screwneck of the lamp when inserted therein, as will be evident from Figs. 1 and 2. (See also Fig. 7.) The upper end of the spindle is secured to a small circular metallic disk, platform, or turntable 'a, the under side of which norm ally rests on a metallic tongue or prong 0, projecting from the leg 70 of the ring h, as best shown in Fig. 2. Now, one of the circnit-wires connects to the leg 71'! as shown by full and dotted lines in Fig. 2, and is hence in metallic connection with the prong 0, while the other wire connects to the bracket Z, as seen in Figs. 1 and 2, and ishence in connection with the table a, so that therefore when the table at is in contact with the prong 0, as seen in Fig.

ICO

2, which is always the case when the lamp is removed from the socket a, the circuit will therefore be closed through the contacts or. 0, and the current thus maintained to the other lamps, which are in their holders and in the same circuit. It will be understood, however, referring to Figs. 1 and 2, that when the lamp is inserted in the holder the end of the screwneek on the lamp in being screwed home in the socket a will contact with the head m of the spindle m, and thus ultimately lift the table or off the contact-prong 0, thus breaking the short circuit between at and 0 and at the same time putting the lamp itself in circuit, for of course the socket a and head on form the two terminals of the circuit in the holder, which thus contact with the two terminals on the screw-neck of the lamp, and thereby put the lamp in circuit. It will be noted, however, that if reliance were placed solely on the breaking of the short circuit at n o to put the lamp in circuit through the terminals a m, the resistance of the lamp being high, while the separation of n 0 is made comparatively slowly by the screwing in of the lamp, an arc might in some cases form at the separated contacts 91 0, instead of the current flowing through the lamp. I therefore provide a small hand-switch, which will keep the short circuit closed until the lamp is put in and the contacts 0 n are separated and will then break the short circuit instantly, so as to put the lamp in circuit without forming an are at n 0. This switch is shown at p in Figs. 1, 2, and 3, and consists of a small metallic bar pivoted at the middle of the slate disk 6 on the stud 1) (see Figs. 2 and 3) and extends diametrically across the disk, as shown, with its operating end provided with a non-conducting tip projecting through a notch (1 in the casing (Z. (See Figs. 1, 6, and A coiled spring q is fixed at one end to the switch and at the other to a pin q, fixed on the disk e, as seen in Fig. 3, and when the switch is swung around into its closet position against the stress of the spring it enters at each end in the grasp of contact clasps r r, as shown best in Figs. 3 and 5, which clasps are fixed on top of the slate disk and are connected with the opposite circuit-terminals of theholderthat is, one clasp is connected with the leg k of the ring 71,, while the other clasp is connected with the bracket Z, as shown by dotted lines in Fig. 3, so that when the switch is closed it forms a short circuit between the circuit-wires hence when the switch is thus closed the lamp may be freely screwed into the socket to put its contact-terminals into contact with the terminals a m and to separate the contacts n 0, and no current can now fiow through the lamp or across the contacts a o. It will be noted that when the switchis thus swung around into its closed position it will move in the circumferential slot (Z in the casing cl, (see Figs. 6 and 3,) and will be finally sprung up into the notch cl at the end of the slot, as seen in Fig. 6, which will thus hold the switch closed against the tendency of the spring (1 to open the same, so that therefore when the switch is depressed out of the notch in line with the slot the spring will cause it to fly instantly open, thus instantaneously breaking the circuit between the clasps '7' r, and thus putting the lamp in circuit.

\Vhen it is desired to extinguish the lamp, it is only necessary to move back the switch to its closed position, the switch thus serving as the key to light and extinguish the lamps without ever actually breaking the serial circuit. If, on the other hand, the lamp should be removed from the socket while the switch is open, the table n will seat on the contact 0, as seen in Fig. 2, before the terminals a 022/ break contact with the retreating lamp, thus closing the circuit and keeping it intact with the other lamps in the series, and thereby acting as a safety device or safetyswiteh, which prevents any injury to the circuit or extinguishment of the other lamps in case it has been forgotten to close the hand-switch 1) before removing the lamp; hence by these means the lamp may be removed, whether the switch is open or closed, without any injury. Another contingency, however, still remains to be provided for that is, if a lamp in any of the holders should become broken while in use it would be necessary to provide a cut-out or short circuit for the current to the other lamps in the series. This I accomplish by providing the top of the table or with a thin disk or washer s, of waxed paper or similar disruptible insulating-layer, which, as shown best in Fig. l, is preferably held in place by a central screw 8 and an insulatingwasher i. Acontact-springu,fixed to and projecting from the leg 7; of the ring 71, bears at its tip upon the disruptible disk .9, as shown in Figs. 2, 8, and 9. It will therefore be seen that when the current takes its normal path through the intact lamp it cannot pass through the disruptible insulator s to make a short circuit between the spring LL and table it, which are of course of opposite polarities. If, however, the lamp should become broken, the current will instantly jump through the thin insulator with adisruptive action, burning or puncturing a hole through the same, which will permit the spring a to contact with the table n, and thus make a short circuit, which will conduct the current to the other lamps, and thus keep the serial circuit intact. After the broken lamp is removed a new one can be inserted, and by means of a screw-driver the slotted head m of the spindle m may be turned so as to rotate the table a and bring an imperforate part of the insulator .9 under the spring a to set the disruptible cut-out ready for action if again required.

The fixed contact 0 and movable contact 91, operated by the insertion and removal of the lamp, I may call the safety-switch or out out, while the contacts u or, separated by the nal.

thin disruptible insulator s, I may call the disruptive cut-out, and these two features may be combined and arranged in various ways in connection with one or more electric lamps without departing from my invention. For example, one Way of arranging them in connection with a set of twin safety-lamps is shown in Fig. 7, in which case it is designed that only one lamp of the pair can be lighted at once, and if one of the two should break the v that the casing (l is held firmly in position other will become automatically lighted. In this case 1; indicates the hanger or holder, haviug the screw-sockets a, in the throats of which are mounted the movable contact-pushes m, corresponding to the part m in Fig. 2. These pushes m, however, instead of acting on the turn-tablen,holdingthedisruptible insulator, act on contact-springs n, which are respectively fixed to the terminals and rest atthe free ends on the conducting-plate 1); hence when neither of the lamps is in its socket the springs n n will rest on the plate 1; and form a short circuit from terminal to termi- \Vhen, however, either lamp is put in the socket, it will press up the push m, and thus lift one of the springs off the plate 1;, and thus divert the current through the carbon of the lamp, as will be seen by tracing 'the connectionsin Fig. 7that is, if the lamp on the left is inserted the current will flow from terminal by spring a, plate 1), and wire 3 to the lamp-socket and the lamp, and from the lamp by push m m and spring a to terminal If the lamp on the right is inserted, it will be seen that only onewill be lighted, as both springs n will then leave the plate o, and thus compel thecurrent to pass through one lamp only. Now I mount the turn-table a of the disruptive cut-outover the plate 1;

on the spindle 072 which passes down throughlator s from the spring a on the right to the table n, and flow thence by spindle m plate 1), and wire 3 to the lamp on the left, and thence by push m and spring 72/ of said lamp to the opposite terminal thus instantaneously lighting the lamp on the left. If both lamps should break, a short circuit would be made between the terminals directly through both springs to u and the table *a by the disrupting action at both springs, as will be readily understood on reference to Fig. 7. By turning the knob j the perforated or disrupted spots on the insulator maybe removed from the springs and a perfect part of the insulator brought under the same for cont-inued action, as will be understood. It will circling at one end the rim 0 on the head I) be seen that if the lamp in Fig. 7 is removed from its socket the retreat of the push m will lower the contact-spring n on the plate ,1), and thus form a short circuit from termiactually correspond to the same elements in Fig. 2.

Referring to Figs. 1 and 2, it will be noted about the internal parts of the holder by enand abutting against the shoulder on said rim, while the other or narrow end of the easing encircles the hard-rubber nut a, which is screwed over the socket a and has a shouldered rim, which abuts against the narrow end of the casing, as well shown in Figs. 1 and 2. It will therefore be seen that the rubber nut a insulates the external casing from the conducting-socket of the holder, while the slate plate e insulates both the head I) and the casing from the other conducting parts of the holder, so that no shock can therefore be received from the casing. To reduce the possibility of this shock further, I make the casing d of sheet metal, (preferably iron,) which is completely coated with avitreous enamelsuch, for example, as that used on granite ware, which I find makes a perfect electric insulator, and is at the same time fire-proof, imparts a handsome appearance to the holder, and is quite inexpensive, and thus forms a very advantageous feature of my holder. Other vitreous enamels may be substituted, and the coating of enamel may be of any desired thickness.

IVhat I claim as my invention is- 1. In an electric-lamp holder, the movable terminal push m and contact 72, connected thereto, with a contact 0 of opposite polarity on which it normally seats, substantially as shown and described.

2. In a lamp-holder, the combination, with the fixed socket a, forming one polar terminal,

and the movable push m, forming the other terminal, of a contact a attached to said latter terminal, a seating contact 0 of opposite polarity, and a spring tending constantly to close said contacts 71 0, substantially as and for the purpose set forth. a

3. In a holder for electric lamps, the com bination, with the movable conducting-push m, adapted to contact with one terminal of the lamp when inserted in its socket, of the plate 01., attached to said push m and having one polarity, with a thin disruptible insulator s on said plate, and a eontact-sprin g u, resting on said insulator and connected with the terminal of opposite polarity, substantially as and for the purpose set forth.

4. In a holder for incandescent electric lamps, the combination, to form a disruptive cut-out, of a rotary conducting-table connected to one terminal, a thin disruptible insulating layer or disk thereon, and a contacttongue bearing on the opposite side of said disk and connected to the opposite terminal, substantially as set forth.

5. In a disruptive cut-out, the combination, with the rotary table 12, axial spindle m, and bearing Z, of the disruptible insulator s and contact-spring u, arranged and operating substantially as shown and described.

6. In an electric-lamp holder adapted for serial circuits, the combination, with a handswitch arranged, when closed, to form a short circuit between the terminals, of a spring tending constantly to open said switch, whereby when said switch is released it opens instantaneously, substantially as and for the purpose set forth.

7. In an electric-lamp holder adapted for serial circuits, a movable contact-maker arranged in the receiving-socket for the lamp and in the path of the lamp, so arranged that when the lamp is inserted the contact is opened, and vice versa, with a distinct handswitch arranged, when closed, to short-circuit or cut out the lamp and said contaet-niaker, with a spring tending constantly to open said switch, whereby when the switch is released the short circuit is broken instantly and the lamp switched in without danger of arcing at the movable contact-maker, substantially as herein set forth.

8. In an electric-lamp holder, the combination,with a hand-switch arranged,when closed, to short-circuit or cut otl the lamp, of a spring tending constantly to open said switch instantaneously, and a catch to hold said switch closed until designedly released, substantially as and for the purpose set forth.

9. In an electric-lamp holder, the combination, with the insulating-base e, of the ring h and legs 7; k, with the bracket 1, socket a, push m, spindle m, contact '21, and contact 0, substantially as shown and described.

10. The combination, with the head Z) and insulating-plate c, secured thereto, of the ring 71, secured to the plate, socket a, secured to the ring, external casing d, and insulatingnut a, arranged substantially as shown and described.

11. In a disruptive cut-out, the combination, with a rotary conducting-table 'n, disruptible insulator thereon, and contact-tongue bearing upon the same, of an axial spindle extending from said table, a bearing supporting the same, and an operating-head on the end of said spindle, substantially as shown and described.

JAMES J. WOOD.

IVitnesses:

.INo. E. GAVIN, CHAS. M. HIceINs. 

